Measurements of jet quenching and heavy flavor production with the ATLAS detector

Measurements of jet suppression in PbPb collisions by the ATLAS Collaboration are reported. The production of inclusive jet yields as a function of jet pt, collision centrality and jet size parameter R are measured and presented through the central-to-peripheral ratio, Rcp. Jets are found to be suppressed in central collisions relative to peripheral collisions by approximately a factor of two. The suppression is found to show almost no variation with jet pt, and the Rcp is found to increase slighly with increasing R. Measurements of heavy quark energy loss are also presented using muons from semi-leptonic decays of heavy flavor hadrons. The maximal suppression is observed to be Rcp ~ 0.5 and shows no significant depedence on the muon pt.Comment: 8 pages, 4 figures. Proceedings for Hard Probes 2012 Conference, 5/27/12-6/1/12, Cagliari, Ital

Jet Quenching in Relativistic Heavy Ion Collisions at the LHC

Jet production in relativistic heavy ion collisions is studied using Pb+Pb collisions at a center of mass energy of 2.76 TeV per nucleon. The measurements reported here utilize data collected with the ATLAS detector at the LHC from the 2010 Pb ion run corresponding to a total integrated luminosity of 7 µ b^(-1). The results are obtained using fully reconstructed jets using the anti-k t algorithm with a per-event background subtraction procedure. A centrality-dependent modification of the dijet asymmetry distribution is observed, which indicates a higher rate of asymmetric dijet pairs in central collisions relative to periphal and pp collisions. Simultaneously the dijet angular correlations show almost no centrality dependence. These results provide the first direct observation of jet quenching. Measurements of the single inclusive jet spectrum, measured with jet radius parameters R=0.2, 0.3, 0.4 and 0.5, are also presented. The spectra are unfolded to correct for the finite energy resolution introduced by both detector effects and underlying event fluctuations. Single jet production, through the central-to-peripheral ratio R CP, is found to be suppressed in central collisions by approximately a factor of two, nearly independent of the jet p T. The R CP is found to have a small but significant increase with increasing R, which may relate directly to aspects of radiative energy loss

Measurement of Jets and Jet Suppression in sqrt(s_NN)=2.76 TeV Lead-Lead Collisions with the ATLAS detector at the LHC

The first results of single jet observables in Pb+Pb collisions at sqrt(s_NN)=2.76 TeV measured with the ATLAS detector at the LHC are presented. Full jets are reconstructed with the anti-kt algorithm with R= 0.2 and 0.4, using an event-by-event subtraction procedure to correct for the effects of the underlying event including elliptic flow. The geometrically-scaled ratio of jet yields in central and peripheral events,Rcp, indicates a clear suppression of jets with ET >100 GeV. The transverse and longitudinal distributions of jet fragments is also presented. We find little no substantial change to the fragmentation properties and no significant change in the level of suppression when moving to the larger jet definition.Comment: 5 pages, 6 figures, proceedings for Quark Matter 2011, Annecy, France, May 23-28, 201

Expansion of CD25-Negative Forkhead Box P3-Positive T Cells during HIV and Mycobacterium tuberculosis Infection

Tuberculosis (TB) and HIV alter the immune system, and coinfected (HIV-TB) individuals usually present deregulations of T-lymphocytic immune response. We previously observed an increased frequency of “unconventional” CD4+CD25−FoxP3+ Treg (uTreg) population during HIV-TB disease. Therefore, we aimed to explore the phenotype and function of uTreg and conventional CD4+CD25+FoxP3+ Treg subsets (cTreg) in this context. We evaluated the expression of CD39, programmed cell death protein 1 (PD1), glucocorticoid-induced tumor necrosis factor receptor (GITR), and the effector/memory distribution by flow cytometry in cTreg and uTreg. Also, IL-10, TGF-β, IFN-γ production, and the suppressor capacity of uTregs were analyzed in cocultures with effector lymphocytes and compared with the effect of regulatory T cells (Tregs). We found diminished expression of CD39 and higher levels of PD1 on uTreg compared to cTreg in both HIV-TB and healthy donors (HD). In addition, uTreg and cTreg showed differences in maturation status in both HIV-TB and HD groups, due to the expansion of effector memory uTregs. Interestingly, both HIV-TB and HD showed a pronounced production of IFN-γ in uTreg population, though no significant differences were observed for IL-10 and TGF-β production between uTreg and cTreg. Moreover, IFN-γ+ cells were restricted to the CD39− uTreg population. Finally, when the suppressor capacity was evaluated, both uTreg and cTreg inhibited polyclonal T cell-proliferation and IFN-γ production in a similar extent. These findings suggest that uTregs, which are expanded during HIV-TB coinfection, exert regulatory functions in a similar way to cTregs despite an altered surface expression of Treg characteristic markers and differences in cytokine production.Fil: Angerami, Matias. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Biomédicas en Retrovirus y Sida. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones Biomédicas en Retrovirus y Sida; ArgentinaFil: Suárez, Guadalupe Verónica. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Biomédicas en Retrovirus y Sida. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones Biomédicas en Retrovirus y Sida; ArgentinaFil: Vecchione, María Belén. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Biomédicas en Retrovirus y Sida. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones Biomédicas en Retrovirus y Sida; ArgentinaFil: Laufer, Natalia Lorna. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Biomédicas en Retrovirus y Sida. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones Biomédicas en Retrovirus y Sida; ArgentinaFil: Ameri, Diego. Gobierno de la Ciudad de Buenos Aires. Hospital General de Agudos ; ArgentinaFil: Ben, Graciela. Gobierno de la Ciudad de Buenos Aires. Hospital General de Agudos ; ArgentinaFil: Perez, Hector. Gobierno de la Ciudad de Buenos Aires. Hospital General de Agudos ; ArgentinaFil: Sued, Omar Gustavo. Fundación Huésped; ArgentinaFil: Salomon, Horacio Eduardo. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Biomédicas en Retrovirus y Sida. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones Biomédicas en Retrovirus y Sida; ArgentinaFil: Quiroga, María Florencia. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Biomédicas en Retrovirus y Sida. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones Biomédicas en Retrovirus y Sida; Argentin

Olho seco causado por infecções virais: revisão

Dry eye disease and ocular surface disorders may be caused or worsened by viral agents. There are several known and suspected virus associated to ocular surface diseases. The possible pathogenic mechanisms for virus-related dry eye disease are presented herein. This review serves to reinforce the importance of ophthalmologists as one of the healthcare professional able to diagnose a potentially large number of infected patients with high prevalent viral agents.A síndrome do olho seco e as doenças de superfície ocular podem ser causadas ou agravadas por agentes virais. Diversos vírus são causadores ou tem associação suspeitada com as doenças de superfície ocular. Esta revisão apresenta os possíveis mecanismos patogênicos envolvidos no olho seco causado por infecões virais e reinforça a importância do oftalmologista como um dos profissionais de saúde capazes de diagnosticar um grande número de pacientes infectados por agentes virais altamente prevalentes.12913

Experiments C02 /OGO 2/ and D02 /OGO 4/ Final report, 2 Nov. 1962 - 31 Jul. 1969

VLF data from OGO 2 and OGO 4 on propagation, wave-particle interactions, and noise in ionosphere and magnetospher

UMA ABORDAGEM CONVIDATIVA PARA O DEBATE COMPLEXO DAS MASCULINIDADES POR JJ BOLA

Resenha da obra: BOLA, Jj. Seja homem: a masculinidade desmascarada. Tradução de Rafael Spuldar. 2º edição. Dublinense: Porto Alegre, 2020